A Study on the Degradation Mechanisms of Honeycomb Structure by Moisture Absorption

摘要

Honeycomb structure, which are composed of FRP panels and a honeycomb core, are the superior materials because of their high specific characteristics and outstanding properties. Although the structures hve advantages for applications, some failures of structures have been repeatedly reported by moist absorption. Therefore, it is necessary to find out the degradation mechanisms of honeycomb structure in order to ensure their reliability. In this study, two types of specimens (non-hole specimens and hole specimens) were manufactured, and immersed for 16weeks in the water bath. In addition, Flatwise tensile (FWT) testing and fractographic analysis were conducted to find out the degradation mechanisms of honeycomb structure. The different behavior associated with the strength reduction between non-hole specimens and hole specimens could be observed by FWT testing. In case of non-hole specimens, the resin types of their FRPs were the most important factors in mechanical degradation of the bonding strengths. Moreover, relatively fast FWT reductions and continuing reductions could be observed in hole specimens.